OBJECTIVETo study the preparation of ginkgolic a ci d(GA) monomers from sarcotestas of Ginkgo biloba for applied research and qu antitative analysis of GA.METHODSGA were extracted by petro leum ether reflux extraction from sarcotestas of Ginkgo biloba.The extracts were separated by silica gel column and the mixture of GA was obtained.Then the GA mixture was isolated by preparation chromatography repeatedly and monomers we re obtained.RESULTSThe yield,purity and extraction ratio of GA by petroleum ether r...